1. Field of the Invention
The present invention relates to a vacuum cleaner, and more particularly, to a cyclonic dust collection unit, which is accommodated inside a vacuum cleaner. Further, the present invention relates to a filter structure of a cyclonic dust collection unit, which is accommodated inside the cyclonic dust collection unit to filter relatively large foreign object.
2. Description of the Related Art
A vacuum cleaner is used to clean a room or other spaces by sucking air containing foreign objects and filtering the foreign object using vacuum pressure generated therein. In order to filter the foreign objects contained in the sucked air, a dust collection unit with a filtering unit is provided in the vacuum cleaner.
The filtering unit is classified into a porous filter formed of porous material and a cyclone type filter. The porous filter formed of porous material is designed to filter the foreign objects contained in air while the air passes through the filter. The cyclone type filter is designed to filter the foreign objects using cyclone airflow. In order to reuse the porous filter, a user has to clean the filter to remove the foreign objects clogged in the filter. Furthermore, when a large amount of the foreign objects are clogged, the porous filter cannot be reused. Since the cyclone type filter is designed to remove the foreign objects from the air by a rotational air current generated by cyclone airflow, the clogging of the foreign objects in the filter is not incurred. Due to this reason, in recent years, cyclone type filter has been widely used.
In recent years, a multi-cyclone type dust collection unit, in which the cyclone unit is provided in plurality to generate a plurality of cyclone airflows, has been developed. The multi-cyclone airflows improve the foreign object removal efficiency. In addition, since there is no need to additionally provide the porous filter in the dust collection unit, the multi-cyclone type dust collection unit would be advantageous in that the separate filter cleaning is not required.
Also, it is general that the multi-cyclone type dust collection unit is provided, inside the dust collection unit, with a plate type filter for filtering relatively large foreign objects such as a hair or paper piece.
However, in the multi-cyclone type dust collection unit provided with the plate type filter, a long foreign object, such as a hair, wastepaper may be frequently curled on an outer circumference of the plate type filter and piled. When a hair is curled on the filter, cyclonic airflow further increases a curled force, resulting in the hair being wedged on the outer circumference of the filter and never freed from.
Thus, when the amount of foreign objects such as hairs and the like wedged on the outer circumference of the filter increases, a user has to eliminate such foreign objects with a strong force, which is inconvenient.